1. Field of the Invention
The present invention relates to improvements in etch resistance of a surface of a workpiece, such as a surface of a resist film or of a resist pattern for fine patterning. More specifically, it relates to an etch-resistant film that can be arranged typically as an etch-resistant masking material on an underlying layer having low etch resistance, and a method for efficiently forming the same; a surface-modified resist pattern that includes a resist pattern having low etch resistance and a modified surface having high etch resistance and is suitable for fine and high-definition patterning, and a method for efficiently forming the same; and a semiconductor device that has a fine and high-definition wiring pattern and exhibits high performance and high quality, and a method for efficiently manufacturing the same.
2. Description of the Related Art
Smaller semiconductor integrated circuits (large scale integrated circuits; LSI) translate shorter wavelength of irradiating light sources. For example, argon fluoride (ArF) excimer laser having a wavelength of 193 nm is used in 90 nm-node devices. With shorter wavelengths of irradiating light sources, acrylic materials having higher transparency in the region of shorter wavelengths than conventional phenol materials have been increasingly used as resist materials for fine patterning. Fluorine (F2) excimer laser having a wavelength of 157 nm will be used for 65 nm-node devices in the future, and fluorine-containing norbornene resists and acrylic resists have been increasingly developed as resist materials enabling such fine patterning.
These resists for use in argon fluoride (ArF) excimer laser lithography, such as acrylic resists and norbornene resists for corresponding shorter wavelengths, however, are inferior in plasma-etch resistance in processing to conventional phenolic resists. To improve the etch resistance of such a resist for use in argon fluoride (ArF) excimer laser lithography, therefore, introduction of a polycyclic alicyclic compound having a low absorption coefficient in the region of wavelength in lithography into a base resin of the resist has been proposed. The resulting resist, however, cannot significantly have transparency and etch resistance equivalent to those of the conventional phenolic resists. The resists typically for use in argon fluoride (ArF) excimer laser lithography have insufficient etch resistance and must employ complicated processes using, for example, a tri-level (three-layered) hard mask in processing of LSI. A two-level (two-layer) resist process using a Si-containing resist is also known as an alternative solution of the complicated multi-level process. This technique, however, invites a residue typically of SiO2 remained in the Si-containing layer after etching and has not yet been used in practice. In contrast, a technique of depositing a silicone resin on a resist by application of ion beams has been proposed (e.g., Japanese Patent Application Laid-Open (JP-A) No. 08-31720), but it also invites a residue after etching, as in the two-layer resist process.
No technique has been provided to improve the etch resistance of a surface of a workpiece, such as a surface of a resist film or a surface of a resist pattern for fine patterning, without inviting unnecessary residues during etching. In addition, no technique has been provided to carry out etching using a resist for use in argon fluoride (ArF) excimer laser lithography as a mask without requiring complicated processes.
Accordingly, an object of the present invention is to provide an etch-resistant film that can be suitably arranged typically as a masking material against etching on an underlying layer (surface of a workpiece) having low etch resistance, and a method for efficiently forming the same.
Another object of the present invention is to provide a surface-modified resist pattern which contains a resist pattern having low etch resistance but having a modified and etch-resistant surface and is suitable for fine and high-definition patterning, and a method for efficiently forming the same.
Yet another object of the present invention is to provide a semiconductor device having a fine and high-definition wiring pattern and exhibiting high performance and high quality, and a method for efficiently manufacturing the same.